I write a lot about well-intentioned tests and treatments for patients leading to (unintended but very real) negative consequences.

For example: high cholesterol is linked to heart attacks and heart attacks kill. We have a kind of drug that lowers cholesterol (statins). Give the drug, lower the cholesterol, lower the number of heart attacks. So, we put everyone on statin drugs, yay!

Except, no. Physiology is not logic; lowering cholesterol with statins may NOT lower the number of heart attacks or it may not do so in most people. And statins don't actually save lives in people who don't already have heart disease. But many people (~1/10) given this statin drug will experience unpleasant side effects, like daily muscle cramps. (theNNT.com)

That understood, it should not be surprising to see this thinking error applies not only to physiology but also to the health care system, a system (like the human body) that does not follow the simple rules of logic.

Well-intentioned quality or performence measures can lead to unintended and very negative consequences. This NY Times article, Giving Doctors Grades, illustrates this problem perfectly.

While trying to ensure high quality care, some metrics are set. These metrics are meant to be measured repeatedly to ensure that whatever changes are made result in better and better patient outcomes, lower costs, etc. Unfortunately, the choice of metrics can drive physicians to behave badly, in order to score higher on their report cards. To get the best outcomes, surgeons stop helping the sickest people and surgerize the healthy instead.

Bad things happen to patients that did not need things done to them.

My own provincial medical association, Doctors of BC, and many other organizations in Canada have discussed measuring physician performance. We as physicians want to be accountable to our patients, and the public wants this too. Our common goal: that dangerous, unsafe practices be weeded out and high quality care be supported and applauded.

We must proceed very very carefully when we put measurements in place lest we incentivize the wrong thing and do more harm than good.